Here's a collection of vero (stripboard) and tagboard guitar and bass effect layouts that we have put together covering many classic and popular effects in growing numbers. Many of these have been posted on freestompboxes.org, so check that site out for great discussions on building your own effect pedals. Enjoy the builds and please also visit us on Facebook and Twitter

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Monday, 9 June 2014

Tiny Giant Amp

Requested by a few people on the forum, this is a mini amp circuit by Taylor Livingston with a bit more ooomph than the others on here, giving 20 watts into a 4 ohm speaker, or 12 watts into an 8 ohm.

Designed to run off a laptop power supply which I'm sure we all have hanging around the house from old broken laptops, with a LM338T taking that down to a regulated 11.6V to supply the opamp and amplifier. The pins of the TDA7240A will need offsetting slightly so it is suitable for vero, but it can be done easily enough, as checked by Lazy Swamis on the forum.

Details of the project can be found here, and there is plenty of discussion to read through if you want to at diystompboxes.

44 comments:

The MAX1044 is rated for a maximum 10V supply, the ICL7660S can take up to 12V. Apart from that it would be fine, personally I prefer the peace of mind you get from the extra capacity from the ICL7660S, and they're also much cheaper.

You can't use them in this though, it will be too much current for them.

got everything ordered or arrived. 1590A friendly for sure. I think I'll just zip tie the Tiny Giant on top of the reverb tank in my old vibrolux.The next time the old girl starts acting up in the middle of the show, I'll let her rest a bit.Thanks a heap lvlark!

Am I right in thinking I could put any preamp (is one of ROG's JFET emulations) before the volume control instead of the TL072 pre?

If that's the case I think many people would enjoy a very layout for the post volume amp section only (which I assume is as per the TDA7240A data sheet?) to try some options out, tweak or create multiple pres monster mini amps *wink wink* :)

Here is a mod to just use a 12v power supply, and get rid of the regulator. Could I just follow these same instructions when using your layout? Omit the 1K and 120R resistors, and connect the 2 legs of the regulator pads?

I just got this all put together and am having trouble getting it working :-/ A few questions:

1) What is the proper pinout of the amplifier? Numbering 1-7 isn't very informative, though I'm not entirely sure that's my problem.2) How am I supposed to connect the amplifier and regulator to a heatsink if they are sideways in the middle of the circuit?3) How are the speaker 1 and 2 supposed to be hooked up? To those correspond to - and + terminals of a speaker? Please clarify.4) Related: is speaker - allowed to be grounded? I would like to turn it into a 1/4" output so I can drive a cab with it like a head.5) Will someone please just take a picture of a completed build so I can double check mine? :-/

anyone get this one working? i was thinking that it would be awesome to put the preamp section for whatever amp you really want in front of this and you can essentially have a mini version. like putting an orange preamp in front could give you a mini 20watt orange that can fit in a guitar case.

I've got this layout working. A few words to the wise. .. . First, verify that your power supply can provide 4A or better. I neglected to check that and tried to make it work with a 2.6A supply and it just won't make any useful sounds that way. If you've got a big enough laptop supply laying around, you're in luck. If not, you're going to have to spend some money to power this thing. Next, you have to keep your signal wires away from your power wires away from your speaker wires, or you will experience a lot of noisy, crosstalky shit. Finally - get your heat sinks squared away before you start trying to power this up/troubleshoot it, lest you cook your ICs before you ever get it working.

how did you fit the heat sinks inside the layout ?i tried firing it up without the heat sinks...got kind of a floppy sound then a high pitch squeal ...the guitar sound is coming thru thowe with allot of distortion and low volume with allot of heat.

ok so i installed the heat sinks and im still experiencing issues.im getting some floppy sound at about 60 hz frequency. it sounds similar to driving in a high speed with one of the windows in the back open.the guitar sounds very weak and distorted and still it goes to a high pitch squeal after a few seconds... you know what can explain this ? i'm running it thru a 3.17ohm 8 inch speaker.

https://dl.dropboxusercontent.com/u/35159092/20140809_173008.jpghttps://www.dropbox.com/s/89q4nwu3s1ish67/20140809_173016.jpgi have provided with a few pics...can this problem be related to heat dissipation ?maybe my heat sinks our not sufficient ? i noticed that the ics our getting really hot while the metal boards i use are not heating up so much ?

I have a working layout that positions the 2 chips at one end of the board for heatsinking purposes. See here for details:http://www.diystompboxes.com/smfforum/index.php?topic=89687.msg983965#msg983965

Ugh. I started having problems with my build, cutting out plus intermittent if you nudged the power amp IC. During troubleshooting I broke one of the leads off the TDA7240 I got from China on ebay. I have since broken the leads on 2 more of them trying to replace it. I suspect I got some crappy ICs, they're barely rugged enough to install in a build. Be careful. Not sure where to look for better ones. Futurlec has them, not sure whether to expect theirs to be any different.

I'm doing something wrong here. Immediately after powering up the TDA7240 went up in smoke. I mean a TON of smoke.

I did try to bypass the regulator and just use a 12v power supply. I read that to do this you can just omit the 1K and 120R resistors, and connect the I and O of the regulator? But that was for the PCB. Did I do something wrong doing with this vero layout?

Kinski - make sure you don't have something shorted to ground that's not supposed to be - like a wrong connection/solder bridge/missing cut at the board, or a metal bodied speaker jack connecting to ground, for example.

hey all,i apologize in advance for my english.i have built this little beauty for the second time now and still no success.the thing works in very very low volume. but when i try to turn the volume up a bit or sturm a few strings together i get this repeating pop sound.

i build this with a slightly larger vero layout to accommodate the heat sinks. i have used monolithic capacitor for the 1u values.i tried looking for bridges mis matched components and such with no lucki replaced the amp chip the power regulator the ic and the power supply and got the same results with all of them.

The Marshall 3005 Lead 12 was a mini-stack with a 12 watt solid state head made in England between 1988 and 1991. People claim it's a gr...

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Not all these layouts are verified and some are put together from unverified schematics. So if you have good luck, or bad luck for that matter, then please let me know by dropping a comment in the topic. Thanks.

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